1. Field of the Invention
The invention relates to the recovery of uranium from phosphate ores. More particularly, it relates to the recovery of uranium from crude phosphoric acid using concentrated solutions of sodium carbonate and sodium bicarbonate.
2. Discussion of the Prior Art
It is well known that Florida phosphate ores contain a minute quantity of uranium. Nonetheless, it is economically feasible to recover the uranium, and this is conventionally done by preparing phosphoric acid and extracting the uranium with solvents such as tributyl phosphate.
Another method for concentrating uranium comprises neutralizing crude phosphoric acid with ammonia. Such "crude phosphoric acid" has been reacted, as a step in its manufacture, with sulfate ion, either from sulfuric acid or from ammonium sulfate, to precipitate most of the calcium as gypsum. Uranium concentrates in the precipitate which forms on ammonia addition. Such ammonia precipitates are formed during the process for making fertilizers. Generally, in the production of fertilizers, the ore is reacted with nitric acid and sulfuric acid and then is ammoniated. A more detailed description of such fertilizer process is taught in U.S. Pat. No. 3,813,233, which, for completeness, is incorporated herein by reference.